#include <unistd.h>
#include <iostream>
using std::cerr;
using std::cout;
using std::endl;

void test0(){
    for(int i = 0; i < 1024; ++i){
        cout << 'a';
    }
    /* cout << endl; */
    cout.flush();
    sleep(2);
}

void test1(){
    //cerr不进行缓冲
	cerr << 1;
	cerr << 3;
	sleep(2);
}

int main(void){
    test1();
    return 0;
}
